This invention relates to a device for casting a sheet metal, particularly of a large width, by directly casting and cooling the molten metal.
The conventional method of producing steel sheets or nonferrous metal sheets of large width (for example, 2 to 30 mm in thickness, 500 to 1800 mm in width) consists of first producing a slab 200 to 250 mm thick by the slab continuous casting and then hot-rolling the slab into a sheet of desired thickness. This method, however, requires a large amount of energy for rolling process.
To overcome this drawback, a Hazelett type continuous casting machine (fore instance Japanese Patent Publication No. 33-1206) has been proposed, which has twin belts for supporting the top and bottom sides of the cast sheet metal. With this continuous casting machine, the lateral sides of the cast sheet are supported by the rotating ball-like caterpillars. When casting metals whose cooling performance is good, such as aluminum and copper, the amount of molten metal that leaks between the caterpillars is small and therefore the casting process can be performed without too great a problem. When, however, this continuous casting machine is applied to the steel material a problem arises. That is, since the thermal conductivity of steel is low the steel molten metal is difficult to be cooled, so that the molten metal easily flows between the caterpillars. Because the adhesion between the caterpillars and the belt is not sufficient, the molten metal that entered between the caterpillars will easily leak out from between the caterpillars and the belt. Thus desired casting cannot be obtained.